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Flu Vaccine Fell Short for Seniors This Season

WebMD News from HealthDay

WebMD News Archive

By Steven Reinberg

HealthDay Reporter

THURSDAY, Feb. 21 (HealthDay News) -- The flu vaccine has fallen markedly short of expectations for older Americans this winter, offering this vulnerable population protection against the most virulent strain of flu virus just 9 percent of the time, U.S. health officials reported Thursday.

Even among the general population, the vaccine's effectiveness was just 56 percent, which is considered slightly below average, according to the latest data from the U.S. Centers for Disease Control and Prevention.

Complicating matters, the 2012-13 season has turned out to be one of the more severe flu seasons in recent years because of the presence of the H3N2 virus -- a strain associated with severe bouts of influenza.

"This was really a worse-than-average flu season," said CDC spokesman Tom Skinner. "It hit the elderly particularly hard. We saw a lot of hospitalizations and, unfortunately, a lot of deaths of the elderly."

"For reasons we don't fully understand, the efficacy rate in those 65 and older against H3N2 was lower than what we would like," he said.

This makes it even more important for the elderly, even if they've been vaccinated, to seek treatment early with antiviral drugs like Tamiflu when they come down with the flu, Skinner said.

Dr. Marc Siegel, associate professor of medicine at NYU Langone Medical Center in New York City, agreed that it's "not an ideal vaccine, but it offers a public health advantage -- it's worth taking."

"The reason this vaccine is not that effective for the elderly is because it's hard for the elderly to mount an immune response," he added.

The vaccine is most effective against influenza B viruses, reaching a level of 67 percent protection both overall and among seniors, the CDC report showed.